from models import get_db, Student, RollCallRecord, OrderCallStatus
from utils import ProbabilityCalculator, ScoreCalculator, ExcelService
import pandas as pd
from sqlalchemy import desc
import matplotlib.pyplot as plt
import io
import base64

class RollCallService:
    def __init__(self):
   
        self.probability_calculator = ProbabilityCalculator()

    def import_students_from_excel(self, excel_file):
        db = next(get_db())
        try:
            df = pd.read_excel(excel_file, engine='openpyxl')
            required_cols = ['学号', '姓名', '专业', '班级']
            if not all(col in df.columns for col in required_cols):
                return False, "Excel缺少必填列（学号、姓名、专业、班级）"

            for _, row in df.iterrows():
                student = Student(
                    student_id=str(row['学号']),
                    name=str(row['姓名']),
                    major=str(row['专业']),
                    class_name=str(row['班级'])
                )
                existing = db.query(Student).filter_by(student_id=student.student_id).first()
                if existing:
                    existing.name = student.name
                    existing.major = student.major
                    existing.class_name = student.class_name
                else:
                    db.add(student)
            db.commit()
            return True, f"成功导入 {len(df)} 名学生"
        except Exception as e:
            db.rollback()
            return False, f"导入失败：{str(e)}"
        finally:
            db.close()

    def roll_call(self, class_name, call_mode='random'):
        db = next(get_db())
        try:
            students = db.query(Student).filter_by(class_name=class_name).order_by(Student.student_id).all()
            if not students:
                return None, "没有找到该班级学生"

            if call_mode == 'random':
                selected = self.probability_calculator.weighted_random_selection(students)
            else:
                status = db.query(OrderCallStatus).filter_by(class_name=class_name).first()
                if not status:
                    status = OrderCallStatus(class_name=class_name, current_index=0)
                    db.add(status)
                    db.commit()
                selected = students[status.current_index % len(students)]
                status.current_index += 1
                db.commit()

            selected.call_count += 1
            db.commit()
            return selected, ""
        except Exception as e:
            db.rollback()
            return None, f"点名失败：{str(e)}"
        finally:
            db.close()

    def update_student_score(self, student_id, answer_type, performance, status='present'):
        db = next(get_db())
        try:
            student = db.query(Student).filter_by(student_id=student_id).first()
            if not student:
                return False, 0

            score_delta = ScoreCalculator.calculate_score(answer_type, performance)
            if status == 'present':
                score_delta += 1

            student.total_score += score_delta
            record = RollCallRecord(
                student_id=student_id,
                call_mode='random',
                status=status,
                answer_type=answer_type,
                performance=performance,
                score_delta=score_delta
            )
            db.add(record)
            db.commit()
            return True, score_delta
        except Exception as e:
            db.rollback()
            return False, 0
        finally:
            db.close()

class ScoreService:
    def __init__(self):
        # 不在初始化时获取db连接
        self.excel_service = ExcelService()

    def get_class_ranking(self, class_name):
        db = next(get_db())
        try:
            return db.query(Student).filter_by(class_name=class_name).order_by(desc(Student.total_score)).all()
        finally:
            db.close()

    def generate_score_chart(self, class_name, top_n=5):
        db = next(get_db())
        try:
            students = self.get_class_ranking(class_name)[:top_n]
            if not students:
                return None

            plt.rcParams['font.sans-serif'] = ['SimHei']
            plt.rcParams['axes.unicode_minus'] = False

            fig, ax = plt.subplots(figsize=(8, 5))
            names = [s.name for s in students]
            scores = [s.total_score for s in students]
            call_counts = [s.call_count for s in students]

            x = range(len(names))
            ax.bar(x, scores, alpha=0.7, label='总积分', color='#3498db')
            ax2 = ax.twinx()
            ax2.plot(x, call_counts, color='#e74c3c', marker='o', label='点名次数')

            ax.set_xlabel('学生姓名')
            ax.set_ylabel('总积分', color='#3498db')
            ax2.set_ylabel('点名次数', color='#e74c3c')
            ax.set_title(f'{class_name} 积分TOP{top_n}及点名次数')
            ax.set_xticks(x)
            ax.set_xticklabels(names, rotation=45)

            buffer = io.BytesIO()
            plt.tight_layout()
            plt.savefig(buffer, format='png', dpi=100, bbox_inches='tight')
            buffer.seek(0)
            img_base64 = base64.b64encode(buffer.getvalue()).decode('utf-8')
            buffer.close()
            plt.close()  
            return img_base64
        finally:
            db.close()

    def export_scores_excel(self, class_name):
        students = self.get_class_ranking(class_name)
        return self.excel_service.export_detailed_scores(students)